Effect of swift heavy ions irradiation on physicochemical and dielectric properties of chitosan and chitosan-Ag nanocomposites

• Published in: Radiation physics and chemistry (Oxford, England : 1993) Vol. 181; p. 109288
• Main Authors: Patel, Gnansagar B., Singh, N.L., Singh, Fouran, Kulriya, P.K.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-04-2021; Elsevier BV
• Subjects: Absorption spectra; Biodegradability; Chitosan; Chitosan–silver nanocomposites; Crystallites; Degassing; Dielectric properties; Dielectric spectroscopy; Fluence; Functional groups; Heavy ions; Irradiation; Molecular interactions; Morphology; Nanocomposites; Nanoparticles; Physicochemical properties; Silver; Swift heavy ions irradiation; Ultraviolet radiation; Swift heavy ions irradiation; Dielectric spectroscopy; Chitosan; Chitosan–silver nanocomposites; Physicochemical properties
• ISSN: 0969-806X; 1879-0895
• DOI: 10.1016/j.radphyschem.2020.109288

Self-sustained films of biodegradable chitosan (CS) and chitosan-Ag nanocomposites (CSN) were prepared by chemical route followed by C+5 and Ni+7 ions irradiation with varying fluences. The crystallite size decreased from 11.1 to 2.7 nm for CS and 17.6 to 14.2 nm for CSN with increasing ions fluence as observed from the analysis of X-ray Diffraction (XRD) spectra. ATR-FTIR spectra revealed assorted vibrational modes and degradation of polymeric chains in both, CS and CSN matrices upon irradiation. The molecular interactions between main and side-chain functional groups impeded due to nanoparticles confining effects. MeV ions yield low-molecular-weight fragments with degassing of some volatile gaseous species during irradiation. An acute amendment in absorption spectra ascribed to change in surface color and differential absorbance at the wavelength of 370 nm showing blocking of UV radiation. The formation of conjugated linkages and carbonization of CS and CSN matrices lead to decrease in bandgap. Modifications in the physicochemical properties were found to be in persuasive association with changes in frequency-dependent dielectric responses. The shape parameter was moderately decreased and indicating non-Debye relaxation. The conductivity of CS and CSN matrices enhanced and follows the universal dielectric response. The amendment in surface morphology was also revealed upon irradiation.
•Chitosan and chitosan-Ag NPs matrices were irradiated with C+5 and Ni+7 ions.•XRD and ATR-FTIR studies revealed amorphization and structural degradation.•Bandgap of self-sustained matrices were engineered using suitable beam parameters.•Amendment in relaxation and conduction were related to physicochemical responses.•Functionalized matrices were employed as UV and electromagnetic shielding materials.